Sleep Deprivation may increase risk of Alzheimer’s disease

February 27, 2019 By R. Bart Sangal MD

Sleep Deprivation may increase risk of Alzheimer’s disease

Recent research shows that sleep deprivation increases tau protein in the brain. Tau leads to the neurofibrillary tangles seen in Alzheimer’s disease. By increasing tau, sleep deprivation may increase risk of Alzheimer’s disease.

During brain activity, proteins like tau are produced in
nerve cells and released into the space between nerve cells (interstitial space).
Tau levels in the interstitial space increase during wakefulness and decrease
during sleep. When mice or humans are sleep deprived, the amount of tau
increases by over 50%. Sleep deprivation also causes tau to spread across the
brain.

Two Factors may increase Tau in the Brain with Sleep Deprivation

Two factors may increase tau in the brain with sleep
deprivation. Firstly, when we sleep, the space between brain cells expands, and
activity byproducts are removed from the brain. If we are not getting enough
sleep, not enough of these byproducts (including tau) may be removed. Secondly,
when we are awake, our brain cells are more active and produce more tau. If we do
not get enough sleep, we may produce too much tau.

Medicines to keep mice awake also lead to increased tau in
the brain. When we use stimulants such as caffeine or other drugs such as
amphetamines (AdderallR), we feel the effects of sleep deprivation
less. However, tau still increases in the brain. The stimulants do not prevent
this increase in tau. Therefore, they probably do not help with the increased
risk of Alzheimer’s disease when we do not get enough sleep.

A night or two of decreased sleep time here and there
probably will not change the risk of Alzheimer’s disease. However, depriving
ourselves of sleep and not getting enough time in bed night after night may
well increase our risk of getting Alzheimer’s disease.

In conclusion, there are many good reasons to make sure we
get 7-9 hours of sleep every day. Avoiding Alzheimer’s disease may be yet one
more reason.